Re: big database resulting in small dump

On Fri, Jul 20, 2012 at 11:23 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Lonni J Friedman <netllama(at)gmail(dot)com> writes:
>> On Fri, Jul 20, 2012 at 11:05 AM, Ilya Ivanov <forn(at)ngs(dot)ru> wrote:
>>> I have a 8.4 database (installed on ubuntu 10.04 x86_64). It holds Zabbix
>>> database. The database on disk takes 10Gb. SQL dump takes only 2Gb.
>
>> Its not entirely clear what behavior you expect here. Assuming that
>> you're referring to running pg_dump, then you should just about never
>> expect the size of the resulting dump to be equal to the amount of
>> disk space the database server files consume on disk. For example,
>> when I pg_dump a database that consumes about 290GB of disk, the
>> resulting dump is about 1.3GB. This is normal & expected behavior.
>
> The fine manual says someplace that databases are commonly about 5X the
> size of a plain-text dump, which is right in line with Ilya's results.
> Lonni's DB sounds a bit bloated :-(, though maybe he's got an atypically
> large set of indexes.

I do have a lot of indices. Also, I'm using a lot of partitions, so
there are a relatively large number of tables.